is +=1 thread safe

[AlFire]

Alexander Schmolck wrote:
> AlFire <spamgrinder.trylater at ggmail.com> writes:
> 
>>> The threading module already has a function to return the number of Thread
>>> objects currently alive.
>> I have threads within threads - so it does not suit me :-(.
> 
> How about using a scalar numpy array? They are mutable, so I assume that x +=
> 1 should be atomic.
> 
I ended up with following:

	counter=[]			counter=0

	counter.append(None)		counter+=1

	counter.pop()			counter-=1

	len(counter)			counter

A.